VEHICLE WHEEL HAVING CONCAVE SEGMENTS Background of the Invention 1. Field of the Invention The present invention relates to wheels for use with all terrain vehicles (ATV) and amphibious vehicles, whether recreational or commercial, light or heavy duty, including industrial earthmoving, agricultural or forestry equipment, propelled in soft terrain such as, without limitation, marsh-like or swamp-like mediums, sand and mud and/or fluid mediums. More particularly, the present invention relates to a buoyant wheel having a longitudinal boundary and a circumferential boundary, the buoyant wheel further comprising a central body comprising a buoyant hollow chamber having a plurality of concaved segments in circumferentially spaced relation wherein each concaved segment has a length substantially equal to said longitudinal boundary and adjacent concaved segments merge at said circumferential boundary.

The contour of said hollow sealed chamber maximizes traction in soft terrain, especially very mushy soft terrain, and creates a radial paddle wheel effect in fluid mediums for enhancing mobility of a vehicle forwardly and backwardly.

2. General Background All terrain vehicles (ATV) such as three wheel, four wheel, and even six or more wheel and dual rear wheel models and amphibious vehicles are designed to

traverse all types of soft terrain such as sand, mud, snow, and other shallow water soft terrain mediums. Additionally, amphibious vehicles and all terrain vehicles (ATV) with amphibious operation are capable of operating in high-level fluid mediums. One such all terrain vehicle (ATV) with amphibious operation is disclosed in U. S. Patent No. 4,744,324, by Martinmass, entitled"AMPHIBIOUS ALL TERRAIN VEHICLE (ATV) AND CONVERSION KIT."The invention, by Martinmass, is directed to a self-propelled all terrain vehicle converted to amphibious operation by an amphibious conversion kit. The amphibious conversion kit has rear axle extensions to mount outer rear wheels that dualize the rear wheels of the ATV, and radial paddle elements on the extensions between the dual rear wheels. The use of the terms all terrain vehicle (ATV) and/or amphibious vehicle will sometimes hereinafter be referred to as the"vehicle." Much effort has been put forth to enhance the traction of the vehicle over such soft terrain. The most common approach used is rubber pneumatic tires having a substantially circular outer perimeter with aggressive treads protruding radially from the outer perimeter. As such, these tires present a generally convex surface to the terrain over which they are rolling. Typically, rubber pneumatic tires are used both on soft terrain and on hard surfaces such as paved roads.

Such aggressive treads embed themselves in the soft terrain to create traction. This embedment often causes severe negative environmental impact, leaving deep ruts in the path of travel. However, the height embeddable in the soft terrain oftentimes is insufficient, especially in very mushy terrain, thereby the traction of the treads is deficient to propel the vehicle forward. Moreover, the distance

between such aggressive treads creates a crevice whereby mud, snow, other soft terrain and debris tend to collect and build up. With such build up, the necessary tire traction, by the aggressive treads, for the propulsion of the vehicle over soft terrain is greatly diminished if not completely halted.

For example, U. S. Patent No. 5,178,088, by Howard, entitled"AMPHIBIOUS VEHICLE"discloses wheels having vanes which radiate outwardly and curve counterclockwise. The vaned wheels grip soil or mush and channel water rearwardly to propel the amphibious vehicle forwardly. The invention, by Howard, further discloses that the vanes facilitate paddling action in water.

Another problem with conventional rubber pneumatic tires is their susceptibility to deflation/defloatation when punctured by debris in the soft terrain.

As can be appreciated, deflated rubber pneumatic tires significantly hinder the mobility of ATVs and must be repaired. Repairing such rubber pneumatic tires, which can be much larger than hard surface tires, may be extremely difficult. Not only does the size of such rubber pneumatic tires make changing them difficult, but such difficulty is compounded by the inherent properties of soft terrain, especially very mushy terrain.

Deflation of the rubber pneumatic tire in fluid mediums, especially high-level fluid mediums, is highly undesirable. If one of the buoyant tires of the vehicle deflates/defloates, such vehicle may become submerged to such a depth as to render the vehicle inoperable. While there are rubber pneumatic tires which provide some buoyancy, generally buoyant rubber pneumatic tires do not generate sufficient buoyant force to adequately support the vehicle in high-level fluid mediums.

Another approach used to enhance traction is described in U. S. Patent No.

5,556,487, by Collard, entitled"TRACK DEVICE HAVING WHEEL WIDENING EFFECT."The invention, by Collard, discloses a pneumatic tire having a tread surface across the width of the tire and a plurality of bridge-like longitudinal and rigid traction blades having an inside surface made to rest on the tires across the width of the tread surface and a ground engaging outside surface.

Other patents present in the wheel art are U. S. Patent No. 5,022,711, by Bangert, entitled"AUXILIARY TRACTOR WHEEL FOR INCREASED TRACTION" and U. S. Patent No. 4,674,757, by Martin, entitled"STAIR-CLIMBING WHEEL UTILIZING AN INVOLUTE CURVE CONFIGURATION"which are directed to wheels, but do not meet the needs of the buoyant wheel of the present invention.

The wheel of the present invention addresses the traction, clogging, environmental impact, and deflation problems of the prior art. A key aspect of the wheel of the present invention is that the wheel presents a concave surface to the terrain over which it rolls, effectively inverting the curvature of prior art wheels. This permits a distinctly unique means of travel, rolling from one radial traction-paddle means to the next, on this inverted curvature, accomplishing superior penetration, flotation and traction, as well as minimizing environmental impact. Without limitation, one of the particular applications for the wheel of the present invention is on amphibious vehicles capable of deep water, floating travel in addition to non-floating or"dry land"travel. The requisite buoyant forces to float such vehicles may be achieved partially from buoyancy from the vehicle wheels and partially from the body configuration of the vehicle. Such vehicles advantageously may move themselves

from land to water, and back again, without the need of a"boat ramp", or specially constructed structure to ease movement to and from the water. Rather, such amphibious vehicles should be able to climb the bank of a river or stream. The inverted or reverse curvature of the wheel of the present invention is important in enabling an amphibious vehicle to move through the very deep soft terrain (deeper than the wheel can penetrate to obtain traction) that often exists between hard terrain and water deep enough to attain buoyancy. Other known wheel designs have been unable to overcome the difficulty encountered when returning from deep water to hard ground. This difficulty arises as the wheels and devices heretofore called upon to serve as both ground propulsion and water propulsion units are unable to make the transition between the two forms.

In such amphibious vehicle applications, the curvature of the wheel of the present invention allows it to self-clean as it moves the soft terrain rearward in such a fashion as to allow the vehicle and wheels to continue floating until sufficient buoyancy is eliminated to allow the vehicle to displace sufficient weight on the terrain to begin to carry itself in ground travel mode. The penetration, low ground pressure, buoyancy and traction characteristics of these wheel of the present invention are enhanced over known wheel designs.

Yet another aspect of the wheel of the present invention is the low environmental impact resulting from passage of these wheels. The wheel creates no significant ruts, and the ground travelled is even aerated by penetration and removal of the radial traction-paddle means, thus stimulating renewed growth possibly superior to conditions found before the wheel travelled over the ground.

Summary of the Present Invention The preferred embodiment of the buoyant wheel of the present invention solves the aforementioned problems in a straight forward and simple manner. What is provided is a wheel, for use in soft terrain or fluid mediums, having a circumferential boundary and a longitudinal boundary, comprising: a central body comprising a hollow chamber having a plurality of concaved segments in circumferentially spaced relation wherein each concaved segment has a length substantially equal to said longitudinal boundary and wherein adjacent concaved segments merge at said circumferential boundary.

In view of the above, it is an object of the present invention to provide a wheel having, in cross section, a star-like geometric shape. Nevertheless, the wheel of the present invention should have at least three concaved segments wherein, as any two adjacent concaved segments merge, a radial traction-paddle means is formed.

Another object of the present invention is to provide a wheel which may provide buoyancy to the vehicle on which it is mounted.

Another object of the present invention is to provide a buoyant wheel which serves as a single means capable of maximizing traction over soft terrain, especially very mushy terrain and creating a radial paddle wheel effect in fluid mediums for enhancing the mobility of the vehicle.

A further object of the present invention is to provide a radial traction-paddle means having a wedge-shaped contour wherein such wedge-shaped contour has a height significantly greater than the height of aggressive treads of pneumatic tires for

enhancing traction in soft terrain, especially very mushy terrain.

It is a still further object of the present invention to provide a plurality of radial traction-paddle means wherein any two adjacent radial traction-paddle means are separated by a lull which is not susceptible to buildup of mud, other soft terrain and debris. More specifically, the lulls serve to create a buoyant wheel which has self- cleaning and non-clogging features. The radial traction-paddle means can be studded or serrated if deemed desirable by the user.

It is a still further object of the present invention to provide a buoyant wheel which provides flotation to a vehicle in high level fluid mediums.

It is a still further object of the present invention to provide a buoyant wheel which is non-pneumatic whereby the buoyant wheel is not susceptible to punctures or defloatation.

In view of the above objects it is a feature of the present invention to provide a buoyant wheel which is adapted to be used in combination with conventional all terrain and/or amphibious vehicle tires.

Another feature of the present invention to provide a buoyant wheel which can be easily installed and detached from a vehicle, as desired.

It is a further feature of the present invention to provide a buoyant wheel which is simple and inexpensive to manufacture.

It is a still further feature of the present invention to provide a buoyant wheel constructed of a puncture proof material.

An advantage of the present invention is that the buoyant wheel is constructed of a puncture proof material wherein such puncture proof material

significantly minimizes if not eliminates the risk of deflation and defloatation of such buoyant wheel.

Another advantage of the present invention is that the buoyant wheel has no means susceptible to buildup of mud, other soft terrain and debris to compromise traction in soft terrain even over extended periods of use.

The above and other objects, features and advantages of the present invention will become apparent from the drawings, the description given herein, and the appended claims.

Brief Description of the Drawings For a further understanding of the nature and objects of the present invention, reference should be had to the following description taken in conjunction with the accompanying drawings in which like parts are given like reference numerals and, wherein: FIGURE 1 is a perspective view of the wheel of the present invention; FIGURE 2 is a perspective view of an axle extension means for installing the wheel of the present invention ; and FIGURE 3 is a perspective view of an alternative embodiment of the wheel of the present invention.

Detailed Description of the Preferred Embodiment Referring now to the drawings, and in particular FIGURE 1, a perspective view of the buoyant wheel of the present invention is shown. It is to be understood that references to"buoyant wheel"herein apply to wheels having any degree of buoyancy, whether or not sufficient to fully or partially float the vehicle to which they

are attached, and that the invention is not limited to"buoyant wheels"but includes wheels in fact having a negative buoyancy.

The buoyant wheel of the present invention is designated generally by the numeral 10. Buoyant wheel 10 is adaptable for use with all terrain three wheel, four wheel, six or more wheel, or dual rear wheel vehicle models and amphibious vehicles. For example, buoyant wheel 10 may be installed on the rear axle of the vehicle. Moreover, buoyant wheel 10 may be installed parallel to conventional pneumatic tires on the rear axle for dualizing the rear wheels. Nevertheless, buoyant wheel 10 is adaptable for use on the front driving axle of the vehicle.

Buoyant wheel 10, in the preferred embodiment, is generally comprised of central body 20 and axle connecting means 30 wherein buoyant wheel 10 has a circumferential boundary C and a longitudinal boundary L wherein circumferential boundary C has a radius R1. It is understood that depending upon the materials from which the wheel is made, the vehicle upon which it is installed, and the type of terrain over which it will be used, central body 20 of the wheel of the present invention may be hollow, may be solid, or may be filled with a material such as styrofoam, plastic or the like.

Central body 20, which in the preferred embodiment may be buoyant, in the preferred embodiment is hollow and made of a puncture proof lightweight material such as, without limitation, aluminum, steel, any other metal alloy, or plastic or other synthetic or composite substance wherein such puncture proof material has a sufficient rigidity which is not susceptible to significant deformation when traveling on hard surfaces or when engaging rocks or other obstructions in the soft terrain and

fluid mediums. Central body 20 is sealed watertight and has a sufficient volume to partially or fully facilitate the floatation of the vehicle wherein such vehicle may not have any other means to provide for its floatation. As mentioned above, the present invention may have the hollow central body filled with a material, such as styrofoam or the like.

As shown in Fig. 1, the preferred embodiment of the present invention comprises central body 20 comprising a plurality of concaved segments 21 a, 21 b, 21 c, and 21 d in circumferentially spaced relation wherein each concaved segment has a length substantially equal to longitudinal boundary L and adjacent concaved segments merge at circumferential boundary C. Central body 20 further comprises two end walls 28 (only one shown) wherein the outline of end walls 28 is defined by the contour of central body 20. As concaved segment 21 a merges with concaved segment 21 b, radial traction-paddle means 22a is formed. As concaved segment 21 b merges with concaved segment 21 c, radial traction-paddle means 22b is formed. As concaved segment 21c merges with concaved segment 21d, radial traction-paddle means 22c is formed. Finally, as concaved segment 21d merges with concaved segment 21a, radial traction-paddle means 22d is formed. It is understood, however, that although the particular embodiment shown in Fig. 1 has four radial traction-paddle means, the wheel may have a different number of radial traction-paddle means, such as three, five, six or more.

Since each of the plurality of concaved segments 21 a, 21 b, 21 c, and 21d and each of the plurality of radial traction-paddle means 22a, 22b, 22c, and 22d are identical, only one such concaved segment 21 a and radial traction-paddle means

22a will be described in detail.

Concaved segment 21a has depth D defined by the distance between point P1 and point P2 wherein point P1 and vertex A1 have the same radius R1 with respect to center point P3 and wherein point P2 is the mid point of the line defined by concaved segment 21 a. Moreover, vertex A1, vertex A2, vertex A3, and vertex A4 have the same radius R1 with respect to center point P3. Thereby, vertex A1, vertex A2, vertex A3, and vertex A4 define points on circumferential boundary C, which is a circle. Furthermore, concaved segment 21a has a length substantially equivalent to longitudinal boundary L.

In the exemplary embodiment, concaved segment 21a is shown as having an arc-shaped curvature and depth D. However, depth D of concaved segment 21a may be increased or decreased, as desired. As can be readily seen, increasing depth D of concaved segments 21a and 21 b would increase the height of radial traction-paddle means 22a. Additionally, in lieu of the arc-shaped curvature, some other concaved curvature or concaved contour, which may or may not be symmetrical about a center line therethrough, may be substituted.

As can be appreciated, buoyant wheel 10 of the exemplary embodiment, in cross section, has a star-like end profile wherein such star-like end profile has four points. Nevertheless, the outer perimeter of buoyant wheel 10 should have at least three concaved segments. For example, buoyant wheel 10 may have a deltoid shape, a hypocycloid shape or the like. However, the maximum number of concaved segments is limited by the a radius of buoyant wheel 10 wherein a large number of radial traction-paddle means may be desired for a larger radius wheel.

Moreover, the number of concaved segments should not diminish the radial paddle wheel effect or the self-cleaning and non-clogging features of buoyant wheel 10 wherein the lull between adjacent radial traction-paddle means should not be sufficiently narrow to create a buildup of mud, snow, other soft terrain and debris.

Radial traction-paddle means 22a is formed as adjacent concaved segments 21 a and 21b merge. Such adjacent concaved segments 21 a and 21b define two principal faces 23 and 24 which meet in a sharply acute angle. In other words, principal face 23 and principal face 24 peak and merge at vertex A1. As can be readily seen, principal faces 23 and 24 meeting in a sharp acute angle define a wedge-shaped contour having a height which extends to vertex A1 wherein vertex A1 has a length substantially equal to longitudinal boundary L. Such height of the wedge-shaped contour has increased the depth of the embedment of radial traction- paddle means 22a in soft terrain, especially very mushy terrain to maximize traction.

Depth D of concaved segment 21 a and the distance between any two adjacent radial traction-paddle means creates lull 25a wherein lull 25a is sufficiently deep and wide to prevent buildup of mud, snow, other soft terrain and debris therein. Thereby, the plurality of lulls 25a, 25b, 25c, and 25d serve to provide buoyant wheel 10 with self-cleaning and non-clogging features. As can be appreciated, the contour of the outer perimeter of buoyant wheel 10 has no means susceptible to buildup of mud, snow, other soft terrain and debris, such as, without limitation, small rocks and foliage.

The two principal faces 23 and 24 meeting in a sharply acute angle in combination with the concaved contour of principal faces 23 and 24 create a radial

paddle wheel effect in fluid mediums. Such radial paddle wheel effect enhances the propulsion of the vehicle in a forward direction as well as in a backward direction.

Therefore, the outer perimeter having the plurality of concaved segments 21 a, 21 b, 21 c, and 21 d serve to enhance the mobility of the vehicle in soft terrain, especially very mushy terrain and fluid mediums.

Central body 20 has a length substantially equal to the longitudinal boundary L and a plurality of radial traction-paddle means 22a, 22b, 22c, and 22d having radius R1. The actual length L and radius R1 of central body 20 may vary depending on a number of parameters such as, without limitation, the volume of central body 20, the number of conventional pneumatic tires on the vehicle, and the weight of the vehicle and the number of buoyant wheels 10 of the present invention to be installed on the vehicle. For example, central body 20 may have a length and a radius equivalent to conventional pneumatic tires.

Axle connecting means 30, in the preferred embodiment, comprises circular member 31 having a plurality of bolt members 32 perpendicularly coupled thereto for installing buoyant wheel 10 to an axle flange (not shown) of the vehicle axle (not shown). Axle connecting means 30 is coupled in the center of at least one of the two end walls 28.

Referring also to FIG. 2, a perspective view of axle extension means 40 for installing the buoyant wheel of the present invention is shown wherein axle extension means 40 would serve to dualize the rear axle wheels. Axle extension means 40 comprises first and second disc-shaped members 36a and 36b and rod member 37. First disc-shaped member 36a has coupled in the center thereof one

distal end of rod member 37. Second disc-shaped member 36b has coupled in the center thereof the other distal end of rod member 37. First disc-shaped member 36a has formed therein a plurality of apertures 38 wherein each of the plurality of apertures 38 align with and receive therein a respective one of a plurality of bolt members (not shown) on the axle flange (not shown) of the rear or front axle of the vehicle. Each of the plurality of bolt members (not shown) on the axle flange would receive thereon a nut member (not shown) for securing axle extension means 40 to the axle flange. Other attachment means, permanent or quick-release, are possible.

Second disc-shaped member 36b has formed therein a plurality of apertures 39 wherein each of the plurality of apertures 39 align with and receive therein a respective one of the plurality of bolt members 32. Each of the plurality of bolt members 32 receive thereon a nut member (not shown) for securing buoyant wheel 10 to axle extension means 40.

In operation, at least two buoyant wheels 10 of the present invention are installed on the vehicle. As the vehicle's axles rotate the at least two buoyant wheels 10 are rotated to propel the vehicle forwardly and backwardly. As buoyant wheels 10 rotate, a concave surface is continuously presented to the terrain (characterized by the concaved segments 21 a through 21d), and the wedge-shaped contour of one of the plurality of radial traction-paddle means 22a, 22b, 22c, and 22d is wedged easily and effortlessly into the soft terrain. Just as easily, each radial traction-paddle means is withdrawn from the terrain. More important, each of the plurality of radial traction-paddle means 22a, 22b, 22c, and 22d are capable of being deeply embedded in very mushy terrain so that traction can be had. During

operation, if any of the plurality of radial traction-paddle means 22a, 22b, 22c, and 22d engage a rock or some other obstruction, such rock or obstruction is traversed.

Referring now to FIG. 3, a perspective view of an alternative embodiment of the buoyant wheel of the present invention is illustrated. Buoyant wheel 10 is essentially best suited for use in soft terrain and fluid mediums. However, buoyant wheel 10 may be driven over hard surfaces, such as paved roads, at low speeds.

Nevertheless, to enhance the mobility of the buoyant wheel of the present invention, as hard surfaces are traversed, buoyant wheel 10'further comprises first and second bands 50a and 50b which are circumferentially coupled to central body 20'at vertex A1', vertex A2', vertex A3', and vertex A4'wherein first and second bands 50a and 50b produce a circle around buoyant wheel 10'. As shown, first band 50a is coupled to one end of central body 20'and second band 50b is coupled to the other end of central body 20'. For ease of installation, first and second bands 50a and 50b could be made of semicircular removable sections. Additional bands could also be added to"round out"the form and shape of the attention as to become a conventional cylindrical wheel.

First and second bands 50a and 50b are made of a sufficiently non- deformable or resilient material which would serve to maintain the circular profile of first and second bands 50a and 50b. Also, other band configurations, such as a greater or lesser number of bands placed at different locations, including serrated edges, etc. on the bands, may be used depending on the specific application.

The buoyant wheel 10 or 10'of the present invention provides a number of advantageous features. For example, as can be seen, that mechanism (i. e., the

plurality of radial traction-paddle means 22a, 22b, 22c and 22d) which is embeddable within soft terrain, especially very mushy terrain, to create traction with such soft terrain may have a significantly increased height in comparison to conventional all terrain pneumatic tires thereby maximizing such traction.

Additionally, the radial paddle wheel effect serves to enhance the paddling action in high-level fluid mediums, as well as in marsh-like and swamp-like mediums wherein fluid depths may vary from very shallow to a level whereby the outer perimeter of buoyant wheel 10 would not come in surface contact with the ground. Finally, depending upon the dimensions of buoyant wheel 10, the weight of the vehicle, and the number of buoyant wheels 10 installed on the vehicle, buoyant wheel 10 may allow a vehicle to float in fluid mediums. Therefore, buoyant wheel 10 of the present invention serves to maximize the propulsion of an all terrain and amphibious vehicle in all soft terrains and fluid mediums.

Because many varying and differing embodiments may be made within the scope of the inventive concept herein taught and because many modifications may be made in the embodiment herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.